personally I mostly ignore branding on fans. The things that matter are:Bearing type.
This drastically affects noise and lifetime of the fan. They fall into 5 types. Companies like to invent their own names for the tech, so careful examination of actual function is important.
Edited by bombastinator - 9/7/13 at 2:40am
quietest initial noise numbers, but very rapidly get quite loud. They are even worse if placed flat.They are very cheap though. (or should be) they have the shortest life of all fans.
A sleeve bearing with a groove in the axle designed to spread the lubricant. Much like sleeve except they CAN lie flat.
Cheap and long life, not real quiet though. the more bearings the better, less than 2 will be quite loud.
As quiet or almost as quiet as a new sleeve, but have the longest life of any fan type except maglev. Generally priciy.
Uses a rare earth magnet to levitate the axle. As quiet and longest life of any fan type. Expect to move them to your next case and will them to your kids. They will outlive your computer. Generally even more expensive, and cannot be placed flat. They can also unbalance easily. Do NOT remove any burs or mold marks from the fan. They also need to be occasionally cleaned as enough dirt will unbalance them
Basically all fans are noisy as their blade tips approach sonic velocities. For 120mm fans this is around 1000 rpm. The bigger the fan the lower the number. Higher cu/ft. per min. fans generally run faster and are louder. You will get more mileage keeping your fan slow than you will by buying some exotic blade system. You can undervolt or, better, use software to regulate a higher speed fan to run at the speed you want, and still have spare cooling at the cost of noise if the computer decides it has to have it.Blade shape:
A backswept fan blade will make (slightly) less noise at higher speeds because the tips effectively move slower (yes I know that is illogical) Trailing edge baffles can help as well, but they look so cool they are frequently added without doing the math first and are merely ornamental. As a rule the fans that have a light up option are louder because they care more about looks than math. One company that DID do the math is nocturnus, but they are also THE most expensive fans on the market.Db rating:
Take these with a grain of salt. There are frequently noise ratings printed on the box for 800 and max RPM. A louder Higher RPM fan may not be louder at the speed you run at.